This invention relates to temperature control apparatus for mixed liquid streams of different temperatures, and more specifically to apparatus for equalizing temperature within such a flowing mixture, for detecting and displaying the temperature of the resulting mixture and for controlling the flow of the mixture.
In modern plumbing fixtures it is known to provide variable temperatures to a stream of water by mixing two streams of different temperatures. Thus, by mixing streams of water at two predetermined temperatures it is possible to obtain a resulting stream having any temperature intermediate the two predetermined temperatures by appropriately varying the control settings of valves used in mixing the two streams. However, when applying such variable temperature streams against various portions of the human anatomy, it is often difficult to predict the resulting water temperature merely by a predetermined setting of the mixing valve. There is thus a possibility of unnecessarily scalding or chilling the body when attempting to regulate the water temperature in a bath or shower, for example. Such temperature shocks are uncomfortable and may be unhealthful for the bather.
Moreover, where a container, such as a bathtub, is filled to a predetermined level with water believed to be regulated at a desired temperature, such uncomfortable temperatures lead to the use of additional quantities of water, thereby wasting both water and the energy needed to heat or cool the water.
The prior art has attempted to solve the problem of selecting a desired temperature for a water stream by inserting a thermometer into the flow path of the stream. For example, the U.S. Pat. No. 2,626,524 to Harman discloses a shower spray head assembly containing a thermometer having a dial indicator to display the temperature of water entering the spray head from a pipe. The water is then outlet through a perforated cap.
U.S. Pat. No. 4,161,881 to Raz describes a similar hand-held unit including either a dial or mercury-type thermometric display at its rearward end.
These and other prior art devices thus provide means for measurement of temperature of water or other liquids issuing through a faucet or other outlet. However, such prior art devices typically require the use of specialized structures and, where used with shower spray heads, thus require the use of specially designed shower heads. Additionally, these devices function with the water stream as input thereto from the supply lines. Thus, in the event of a nonhomogeneous mixture of water streams of different temperatures in the supply line, the temperature displayed by the prior art devices may be erroneous.
Prior art devices for indicating the outlet temperature of a mixed water stream thus subject the users thereof to thermal shock in order to observe the temperature reading, require specialized spray heads, are not fully reliable, and are accordingly complex and expensive.
In applicant's prior copending application there is described apparatus including baffles therein for more thoroughly mixing a stream of two components and providing a temperature measurement and display structure for the mixed stream. However, in order to shut off the output stream, the separate control valves in the supply lines for the two streams are required to be closed. Moreover, regulation of flow rate for the output stream requires manipulation of the separate control valves. In both situations, the mixture ratios are affected and readjustment of the mixture is required to maintain the desired temperature.